In recent years, many semiconductor memory devices having memory cells disposed three-dimensionally are proposed as a way of increasing a degree of integration of memory. For example, one conventional kind of semiconductor memory device having memory cells three-dimensionally disposed employs a transistor having a cylindrical column-shaped structure.
There is a risk that, when an erase operation is executed on a semiconductor memory device of the above-described kind, the erase operation is not executed accurately due to a leak current flowing into the memory cells from various kinds of wiring lines.